In cellular radio communication systems, it has always been important for e.g. a system operator to monitor the performance of the end-user services, to identify areas of poor quality and to improve the performance by means of capacity upgrade and network tuning.
There exist radio network nodes which measure so called performance indicators in a system on a statistical basis. This enables the network operator to monitor the performance of the service delivered to the mobile subscribers and to detect areas where the service performance is below an acceptable level. It is also possible for the system operator to find the root cause of poor quality, e.g. an under-dimensioned node such as a radio base station, “RBS”, i.e. a controlling node of a cell in the system, or, for example, faulty parameter settings for handovers in a cell.
In existing systems, e.g. GSM systems, one known way of obtaining a performance indicator for a cell in the system is to measure the amount of successfully transferred data divided by the time used to transfer the data. In this manner, the so called radio link bit rate is obtained.
For LTE systems, Long Term Evolution, it is desired by system operators to obtain more standardized performance indicators, so that measurements can be compared between different LTE vendors. LTE systems are also referred to as E-UTRAN systems.